Abstract: A method is proposed for determining the surface roughness length. In order to obtain z_０, only the fine wind profile observation are required, thus the measurement errors can be quite low. This method is particular useful for circumstances when near-neutral conditions are rare in observation. Based on the atmospheric boundary layer observation over the Gobi desert area in Hexi Corridor, the roughness z_０ is estimated to be 0.60mm, close to the value of 0.78mm obtained by other method, which demonstrates the reliability of the authors' method. Besides, since observation at different height represent characteristics of different surface area, the height should be taken into account when determining the value of surface roughness.

Key words: aerodynamic parameter, Gobi desert surface, surface roughness length, atmospheric stratification, atmospheric boundary layer

摘要： 提出一种确定地表粗糙度z₀的方法。该方法仅需利用精细风廓线资料进行计算，误差较小，尤其适用于近中性层结观测较困难的情况。根据2006年夏季河西走廊戈壁地区的大气边界层观测资料，利用该方法确定的z₀为0.60mm左右，和前人方法计算结果0.78mm接近，证实了此方法和z₀数值的可靠性和可信度。此外，由于不同测量高度代表不同区域尺度上的特征，地表粗糙度的确定还应考虑风廓线的观测高度及分布状态。

关键词: 空气动力学参数, 戈壁下垫面, 地表粗糙度, 大气稳定度, 大气边界层